1. Field of the Invention
This invention relates generally to the field of baling presses and more particularly, to an improved wire tie guide and tying device for a baling press and a method of assembling the wire tie guide.
2. Related Art
Wire baling of bulk materials has benefited from increased speed and reduced material cost through automation. Bulk materials include fibrous bulk materials, such as cotton and nylon. Fibrous materials are commonly formed into bales by simultaneous compression and binding. There is a continuing need in the automated baling art to improve the efficiency, reliability and accuracy of the bale binding process.
Baling wire performance requirements vary depending upon the bulk material being baled. Such requirements range from industry standard specifications to general operational parameters, such as minimum speeds required for profitability. The Cotton Council issues baling constraint standards specifying particular ranges for the length of wire around the bale and the tension that the wire must withstand. These ranges correspond to the weight, volume and compression of various standard bale sizes such as “universal density” or “standard density” bales.
Current automated baling machines use an articulated track to guide wire around bales of bulk material, such as cotton, while the bale is under compression. Material to be baled is typically introduced into the automatic baler under vertical compression. Typical pressures for an industry standard 500 pound, 20×54 inch bale of cotton are in excess of 300 tons. Horizontal plates called follower blocks apply compression through platens which contact the surface of the cotton or other material being compressed. The platens incorporate slots which run lateral to the longitudinal axis of the bale. The Industry Standard number of binding wires for the most common kind of cotton bale, the standard density bale, is six. Accordingly there are six slots in the platens to allow the baling wire to be wrapped around the bale while it is still under compression. Under the lateral slots are lateral channels for insertion of wire guide track sections in both the upper and lower platens in automatic balers.
U.S. Pat. No. 6,363,843 issued to Daniel et al. on Apr. 2, 2002, herein incorporated by reference, discloses a bailing press having a plurality of modular wire guide members connected to the upper platen. As shown in FIG. 1, each wire guide member 44 includes a generally U-shaped channel 48 bounded by a top wall 54 and parallel side walls 56, 58 which depend laterally away from the top wall 54 in a generally perpendicular direction. Each wire guide member 44 also includes a door 64 pivotally mounted on a shaft 66 within a cut-out or slot 68 in the one side wall 58. The door 64 is resiliently biased to a closed position by a spring 70. When in the closed position, the door 64 has an outer surface 72 that is generally co-planar with the bottom surfaces 74 of the side walls 56, 58.
While the modular wire guide member of the '843 patent has vastly improved the state of the art, some problems still remain. In particular, contact between the door 64 and the side wall 56 of the modular wire guide may lead to considerable wear of the side wall 56. If the wear is significant or if the wear creates a burr on the wire guide member, the bailing machine must be shut down for removal and repair of the damaged wire guide member. This is because significant wear may prevent the knot from slipping out properly. If the knot does not slip out properly, the bale of fibrous may hang or “stick” to the upper platen. A hanging bale of fibrous material presents a dangerous situation in that the bale could pivot from the upper platen and swing outwardly to injure passerby.
Additionally, a burr on the wire guide member may catch upon the knot, thereby decreasing its reliability. To remove the damaged wire guide for deburring requires that the entire baling machine be shutdown. If the burr is significant, then the wire guide member may need to be heat treated after it is deburred. Such a process is time consuming, inefficient and expensive.
Finally, the dimensional stability of the chamber where the knot is formed is crucial to obtain consistent high-quality knots. If the wire guide member door shuts too much or too little, then the wire ends will not engage properly to form the knot. As an example, the wire ends may straighten out such that the wire ends interlock as two fish hooks. In that case, the wire must be scrapped, and the bale must be manually fastened, which is inefficient.
In addition to knot quality, unscheduled work stoppage due to problems with the wire guide member is very costly. Stopping the baling machine severely reduces productivity and greatly increases costs of production due to labor costs. Therefore, it would be beneficial to have a maintenance device to allow for scheduled maintenance of the wire guide member.
Thus, there is a continuing effort to provide a more reliable and easy to operate tying device by further simplifying the manipulations required by the user. Further, there is a need in the art for an economical device to address the issue of wear to the side wall as a result of contact between the wire guide member door and the side wall.